Pneumatic operating mechanism for typewriters



Sept. 30, 1930. J R, MacPHERSON ET AL 1,777,212

PNEUMATIC OPERATING MECHANISM FOR TYPEWRITERS Filed Jan. 3, 1927 10 Sheets-Sheet 1 v fys f7 36 l guf, 40

5a 60 V r fizz/anions Sept. 30, 1930. R MacPHERSQN l-TI'AL 1,777,212

PNEUMATIC OPERATING MECHANISM FOR TYPEWRITERS Filed Jan. 3, 1927 10 She ets-Sheet 2 a 6/ 115071; Value; 73, flhc 726751 2, Ja

Sept. 30, 1930. R MHCPHERSON Er AL 1,777,212

PNEUMATIC OPERATING MECHANISM FOR TYPEWRITERS Filed Jan. 3, 1927 10 Sheets-Sheet 3 Sept. 30, 1930. R MacpHERsoN'l-n AL 1,777,212

PNEUMATIC OPERATING MECHANISM FOR TYPEWRITERS Filed Ham. 3, 1927 10 Sheets-Sheet 4 Sept. 3,'1930. R, MaCPHERSON ET AL 1,777,212

PNEUMATIQ OPERATING MECHANISM FOR TYPEWRITERS Filed Jan. 3. 1927 10 Sheets-Sheet 5 ml Q1 J...

Sept 30, 1930. R MacPHERSQN ET AL 1,777,212

PNEUMATIC OPERATING MECHANISM FOR TYPEWRITERS Filed Jan. :5. 192'? 10 Sheets-Sheet 7 I NRIMA Sept 3@, 1930. MacPHERSON ET AL 1,777,212

PNEUMATIC OPERATING MECHANISM FOR TYPEWRITERS 5am. 3Q 1930. R aCP ET AL 3,777,212

PNEUMATIC OPERAT ING MECHANISM FOR TYPEWRIIERS Filed Jan. 3, 1927 ,10 sh t -sheet 9 Sept. 3Q 1934). J. MaoPHERSQN ET AL PNEUMATIC OPERATING MECHANISM FOR TYPEWRITERS,

Filed Jan. 5, 1927 1O Sheets-Sheet 10 MZZZZZZ Patented Sept. 30, 1930 UNITED STATES PATENT OFFICE JAMES R. MACPHERSON AND PAUL E. HILL, OF CHICAGO, ILLINOIS, ASSIGNORS, IBY MESNE ASSIGNMENTS, TO AMERICAN AUTOMATIC TYPEWRITEB 00., OF CHICAGO,

ILLINOIS, A CORPORATION OF ILLINOIS PNEUMATIC OPERATING MECHANISM FOR TYPEWRITERS Application filed January 3, 1927. Serial No. 158,451.

This invention relates to pneumatic operating mechanism for typewriters, and has for its object the provision of operating mechanism which is adapted for use with any typewriter or typewriting machine equipped with the usual key levers.

The present operating mechanism is pneumatically operated. It dispenses almost entirely with mechanical connections, the movements of the several operating parts being accomplished by the use of pneumatic mechanism. For this purpose we prefer to use an air suction or vacuum rather than a pressure or compression, although in principle the diflerences are negligible.

The operating mechanism, forming the subject matter of the present application, which is adapted for connection with any typewriter or key operated typewriting machine does not require the making over or alteration of the typewriter or typewriting machine. The typewriter operation is in all respects the same as when performed by hand, with the possible exception that the speed is greater, the action on the keys is softer and more even, and the work is entirely accurate. The operating mechanism embodies means for returning the carriage of the typewriter to initial position at the beginning of a line and simultaneously rotating the platen so as to advance the paper, and it embodies means for stopping the typewriting operation at one or more selected places whereby the sentence may be finished by an attendant so as to make the letter distinctive and personal to the addressee. The mechanism embodies means for otherwise meeting all of the usual conditions encountered with the transcribing of letters and other instruments.

The mechanism of, the present invention is advantageous, largely in that it is simplified over previous constructions and may be produced at much less expense; it is entirely dependable in operation it operates the typewriter keys with an action which is both firm and soft, thus producing better -workand longer life of the parts; it is quickly applicable to any typewriter or typewriting machine, and it employs very few mechanical connections whereby' to transmit the'necessary mechanical movements, thus reducing to a minimum the wear and tear consequent upon the use of such parts.

With these and other objects and advantages in view, this invention consists in a pneumatic operating mechanism for typewriters and the like, controlled by a motor driven, perforated record, the perforations of which co-operate with slots in a tracker bar for admitting air, under atmospheric pressure, to valves and valve mechanism that control the operation of the several instrumentalities that operate the typewriter. It further consists in a pneumatic operating mechanism for typewriters in which is embodied pneumatically controlled means for returning the carria e of the typewriter to initial position and simultaneously stopping the record driving motor, and pneumatic means controlled by the carriage forstarting the motor again when the carriage has been returned. It further consists in pneu matically controlled means for reversing the action of the motor whereby the record is rewound upon the roll from which it was unwound during the Writing operation of the typewriter, said means also embodying pneu-' matically controlled mechanism for stopping the record strip when fully rewound and subsequently advancing it to an initial position for repeating the work, and stopping the record at such position whereby the attendant may remove the written sheet and insert a blank sheet into the typewriter. It further consists in pneumatically controlled means for rendering the actuating mechanism inactive (with the exception of the motor) during the interval of rewinding of the rec'- ord. It further consists in means whereby the amount of vacuum created may be regulated so as to increase or decrease the speed of the mechanism, and to strengthen or weaken the action on the typewriter keys and other mechanism of the typewriter. The invention further consists in the several novel features in construction, arrangement and combination of parts hereinafter more fully set forth in the following specification and particularly pointed out in the appended claims.

The invention is clearly illustrated in the drawings accompanying this specification, in which:

Fig. 1 is a front elevation of pneumatic operating mechanism for typewriters, embodying a simple form of the present inven tion and showing the same in connection with a typewriter of standard or commercial form;

Fig. 2 is a side elevation thereof;

Fig. 3 is a front elevation of the record rolls, the air motor and transmission gearing which drives the record rolls;

Fig. 4 is a plan of the parts seen in Fig. 3;

Fig. 5 is a detail vertical cross-section taken on the line 5-5 of Fig. 3;

Fig. 6 is a detail front elevation of the transmission gearing for the record rolls;

Fig. 7 is a detail vertical, longitudinal section through a fragment of the action which controls and operates the keys of the typewriter, the line of section being indicated at I 7-7 in Fig. 8, certain parts being shown in front elevation;

Fig. 8 is a detail vertical cross-section taken on the line 8-8 ofFig. 7

Fig. 9 is an enlarged detail cross-section of one of the typewriter key lever bellows and air chest;

Fig. 10 is a detail horizontal section taken on the line 101O of Fig. 7;

Fig. 11 is a view looking from below of one section of the air chest, the lower half of the chest removed on the line 11-11 in Fig. 8;

Fig. 12 is a horizontal section of the air chest section seen in Fig. 10, taken on the line 1212 in Fi 8,,and part of the air chest section being bro en away;

Fig. 13 is a detail vertical cross-section taken through the carriage return bellows mechanism, the line of section being indicated at l3.-13 in Fig. 2;

Fig. 14 is a detail vertical fragmentary section taken on the line 14.14 of Fig. 13;

Fig. 15 is a side elevation of a governor which is employed for controlling certain of the air conduits, one wall of a certain bellows thereof being partly broken away to illustrate parts that would otherwise be hidden from View;

Fig. 16 is a side elevation of said governor with one of its walls removed along the line 16-16 of Fig. 17 to illustrate certain valve mechanism contained in the governor;

Fig. 17 is a detail vertical cross-section taken on the line 17-17 of Fig. 15;

Fig. 18 is a detail horizontal section taken on the line 18-18 of Fig. 17;

Fig. 19 is a detail horizontal section taken on the line 1919 of Fig. 17;

Fig. 20 is a detail horizontal section taken on the line 20-20 of Fig. 17

Fig. 21 is a detail horizontal section taken on the line 2121 of Fig. 17

Fig. 22 is a detail front elevation of one of the typewriter key levers, the actuating bellows therefor and the link connection between the key lever and bellows;

Fig. 23 is a plan of the bellows shown in Fig. 22;

Fig. 241 is a detail vertical section taken through the bellows device which controls the rewinding mechanism, the line of section being indicated at 2424 in Fig. 2;

Fig. 25 is a view of the bellows device seen in Fig. 24: and looking in the direction of the arrow 25 in said figure;

Fig. 26 is a detail View partly in front elevation and partly in vertical, longitudinal section illustrating a fragment of the typewriting carriage and a valve used for starting the air motor'when the typewriter carriage has been returned to initial position at the commencement of a line;

Fig. 27 is a detail side elevation of one of a number of manually operated valves for controlling operation of certain parts of the mechanism Fig. 28 is a detail front elevation of a fragment of the tracker bar; and

Fig. 29 is a diagrammatic view illustrating the various mechanisms, air conduits and control mechanism of the apparatus.

In the embodiment of the invention as illustrated in the accompanying drawings, a horizontal support A, (see Figs. 1, 2 and 3) such as a table or desk top is provided, upon which is mounted a typewriter B of conventional construction. The typewriter includes the usual reciprocable carriage b, the platen b and the usual key levers 6 that operate to transmit motion to the type bars. Before dcscribing in detail the present operating mechanism for the typewriter, we will briefly describe its general construction and arrangement.

Mounted on the table or other support A, is the record supporting and operating mechanism C, and this mechanism includes a motor D, which is arranged to advance the record or record sheet E, across a tracker bar F, thereby bringing theperforations of the record successively 1nto register with the slots of the tracker bar. Adjacent the typewriter, and as a preference below the table A, is the action G, which mechanism embodies pneumatically controlled and operated devices connected to the key levers b of the typewriter. The action G, includes an air chest and key lever bellows, and each bellows is connected to a slot in the tracker bar by an air conduit such as a flexible tube. The interiors of the bellows are connected to the air chest, which in turn is connected to a vacuum pump H, of suitable form, and which operates to maintain a partial vacuum in the air chest and other pneumatic devices. Valve controlled ports or passages lead from the air chest to the several key lever bellows, and

normally these ports are closed, but they are arranged to be opened whenever an associated slot in the tracker bar is uncovered, and air under atmospheric pressure is thereby admitted to the air tube which connects the uncovered slot with its associated bellows device. The motor D, is also connected to the vacuum pump H and is preferablybf the vacuum type of air motor and remains in operation during the timeithat a line is being written, but is stopped and remains at rest during the time that the carriage is being returned to its initial position. The carriage return mechanism includes a carriage return bellows device 1, preferably mounted below the table .A, and connected to the typewriter carriage by flexible connection whereby the carriage may be drawn back to its initial position whenever the carriage return bellows device I, is actuated. Rewind mechanism is included in the record actuating mechanism and said rewind. mechanism includes a clutch shifting bellows device J, connected to a clutch of the transmission gearing. Normally the clutch shifting bellows is inactive, but when a letter or other instrument has been entirely written, said bellows is automatically operated, thereby shifting said clutch and causing the motor to rewind the record, whereby it may be automatically placed in POSitJOIl for again'operating the typewriter as before. The various devices which have to do with the operation of the typewriter are controlled from the tracker bar and the prearranged location of the perforations upon the record, determines the action of the several instrumentalities.

Having'now briefly described the general constructionand arrangement of the mechanism, we shall proceed to describe in detail the embodiment of the invention which we have chosen to illustrate in the drawings.

The air motor and transmission gearing Supported upon the rear of the table A is a frame 25 (see Figs. 1, 2, 3 and 4) preferably composed of upright frame members 26 and horizontal frame. members 27, 28 and supported upon said frame 25, as for instance by brackets 29, 30 is the air motor D. The air motor '-is of conventional type and as shown is composed of five similar units 03, that drive a crank shaft 31, which is connectedto the record rolls by transmission gearing, here shown as comprising a sprocket chain 32 (see Fig. 6) trained over a sprocket wheel 33 on the crank shaft 31 of the motor, and over a sprocket wheel 34 mountedon a countershaft 35, which is journaled in bearings cm a gear frame 36, carried byone of the upright frame members 26. The winding roll for the record is shown at 37, and on the shaft 38 thereof, is a gear wheel 39, which meshes with a pinion 40, which is mounted on the countershaft 35, but non-rotative with respect thereto. For instance, the counterjust described, is such that whenever the motor D isin operation, the record winding roll 37 is rotated in a direction to wind the record thereon and to unwind it from the record rewind roll 41. The record roll 41 is removably mounted upon a short shaft 42, which is also journaled'in bearings on the gearframe 36, and said shaft 42 is shown as connected to the countershaft by a sprocket chain 43 trained over sprocket wheels 44, 45 mounted on the shafts 42, 35 respectively. A clutch connection is provided between the pinion and sprocket wheel 45, which connection may comprise clutch teeth 46, 47 on the pinion 40 and sprocket wheel 45, and a clutch lever '48 is provided for shifting the pinion 40 into and out of mesh with the gear wheel 39 and into and out of connection with the sprocket wheel 45. The clutch shifting bellows device J is connected to the clutch lever 48 and operates to couple the countershaft 35 with the sprocket wheel when the record has completed its passage across the tracker bar, whereby the record will be rewound upon the roll 41 and unwound from the driving roll 37. The construction and operation of the clutch shifting bellows device will be described later on in the course of this specification.

The action or sections 51, and the key lever bellows 52,

their associated valve devices and the key lever link connections 52?. The key lever bellows 52 are provided with slotted arms (see Figs. 22 and 23) through which the link connections 52 extend, and said link connections have shoulders on their lower ends,-here shown in the form of nuts which engage with the lower faces of the arms. The link connections may be readily detached from the arms by moving the link connections out through the slots in the arms. The main air chest 50 is formed with a vacuum chamber 53 (see Fig. 7) and each of the branches or sections 51 thereof is provided w'ith a vacuum chamber 54, which communicates with the vacuum chamber 53 through suitable ports-formed in one side wall of the main air chest 50 as is clearly seen in Fig. 7..

chamber 53 and vacuum pump is a pressure regulating device 56, which governs the flow of air' from the air chest (and its branches) to the vacuum pump. A valve 57 (see Fig. 7) is provided for closing the passage from the main air chest to the pressure regulating device during certain portions of the op eration of the mechanism as will appear later. The pressure regulating device 56 is provided with a bellows 58, the movable wall of which is provided with a valve disc 59 arranged opposite the outlet port from the bellows to the main vacuum pipe 55. This outlet port may be contained in a nipple 60, which may comprise the connection between the flexible tube andthe pressure regulating device 56. The movable Wall of the bellows 58 is under tension and the means for applying the tension may comprise a flat spring 61 connected to the movable wall of the bellows 58 and fulcrumed on a block 62 secured on the stationary wall of the regulating device 56. and a regulating screw 63 hearing against the free end of the spring 61 and threadedly secured in the stationary wall of the pressure regulating device. Obviously by tightening up the regulating screw, the spring is caused to exert greater force upon the movable wall of the bellows 58 thereby resisting to a greater extent the tendency for the bellows to collapse under the influence of the suction therein created by the vacuum pump H. By unscrewing the regulating screw more or less, the tension upon the bellows is lessened and consequently less effort is required to cause the valve 59 to approach the outlet port in the nipple 60. which has the effect of reducing the effective entrance area to said port. By properly adjusting the regulating screw 68 the degree of vacuum created in the air chest, its branches and associated bellows can be regulated.

A passage 64 leads from the interior of the bellows 58, through a port 65 in one wall of the main air chest, to the vacuum chamber 53 thereof. Normally the valve 57 is in a 5 position in which it uncovers the port 65 thereby permitting air to be exhausted from the air chest and its branches, but under certain circumstances the valve 57 closes the port 65 thereby shutting off communication between the air chest and the vacuum pump, thereby rendering inactive the operating mechanism of the action.

The key lever bellows 02, which actuate the typewriter key levers, are secured upon the upper sides of the air chest branches 51 and normally are in open communication with the outer atmosphere and consequently are in their extended condition. Referring to Fig. 9 it will be seen that an air passage 66 leads from the interior of each bellows to a recess or cavity 67 formed in the air chest branch, on whichsaid bellows is secured, and opening to said recess or cavity 67 is an air inlet port 68. The passage 66, cavity 67 and port 68 provide a normally open conduit,

whereby the interior of the bellows is normally in open communication with the outer atmosphere. Between each cavity or recess 67 and the vacuum chamber 54 is a port or passage 69, which leads through the wall between said cavity and chamber, and extending through said port or passage 69 is the stem of a poppet valve 70, the head 71 of which is arranged to normally close the port or passage 69 and under certain circumstances to close the air inlet port 68, and simultaneously open the port 69, thereby shutting 0E communication to the outer atmosphere through the air inlet port 68 and establishing communication between the interior of the bellows 52 and vacuum chamber 54 through the passage 66 and cavity or recess 67, and when this occurs air is exhausted from the bellows 52, which then later col lapses under the influence of the atmospheric pressure thereon, the result being that the key lever connected therewith is depressed. Opposite the end of the poppet valve stem is a recess or pocket 72 from which leads a passage 73 that connects with an air conduit 74, preferably in the form of a flexible tube which leads to a slot g, in the tracker bar that controls the operation of the associated bellows 52. An orifice 75 of restricted size is provided between the vacuum chamber 54 and passage 73, whereby the low pressure in the vacuum chamber 54 may extend to said passage 7 3, the recess 72 and air conduit 7 4. A flexible diaphragm 7 6 is secured to the inner wall of the vacuum chamber 54 and completely covers the recess 7 2. If desired a reinforcement disc 7 7 may be secured to the diaphragm 76 and said disc is arranged to engage the stem of the poppet valve 70. It is to be observed that so long as that tracker bar slot to which the air conduit or tube 74 is connected remains closed, (as for instance, by the record covering'the slot) and whenever a partial vacuum is created in the vacuum chamber 54, a partial vacuum will be created in the air conduit or tube 74, passage 73 and recess 72, whereby the pressure on both sides of the diaphragm 76 is equalized and consequently said diaphragm lies in an inert condition. lVhen, however, said slot in the tracker bar is uncovered, as for instance when a perforation in the record comes into register with it, air at atmospheric pressure is admitted through the air conduit or tube 7'4 and passage 73 into the recess 72, whereupon the diaphragm is forced toward the vacuum chamber 54 the stem of the poppet valve being engaged thereby and the head of the poppet valve unseated, the port or passage 69 thereby opened, and the air inlet port 68 closed, the result being that communication between the interior of the key lever bellows and the external air is closed and communication between the interior of said bellows and vacuum chamber 54 is established through the passage 66 and port 69. The size of the orifice 75 between the passage 73 and vacuum chamber 5 is so small that the action just described is not efiected. It will be understood that the moment the slot in the tracker bar isagain covered, the air in the air conduit or tube 7 4, passage 73 and recess 72 will again be exhausted through the orifice 75, and the partial vacuum restored in said parts, whereupon the poppet valve will be forced back under the influence of the outer external air at atmospheric pressure, and air will thereupon be admitted to the interior of the key lever bellows through the air inlet port 68, recess 67 and passage 66, permitting the bellows to resume the extended position, under the influence of the spring which actuates the key lever of the typewriter.

The air chest has been shown and decribed as formed of a number of branches or sections. Preferably the branches are arranged in tiers with a number of the key lever bellows associated with each branch. By arranging the branches and bellows in this manner space is economized without sacrificing the size and working capacity of the key lever bellows. Since the operating mechanism has been illustrated in connection with a typewriter employing four banks of keys, four tiers of branches and bellows are used in this particular arrangement and the number of bellows on each branch is made to correspond with the number of keys in the bank to which the bellows of each particular tier are connected. It will also be observed that one of the bellows of the upper tier is somewhat larger than the other bellows. This particular bellows is connected to the tabulator key lever, which may require a little more force to operate it than the type key levers, and one of the bellows of the lowermost tier is also made somewhat larger than others of that tier, this bellows being connected to the shift key lever, which also requires a litle more force to actuate it than the type key levers. The entire action is shown as supported by the table A, the upper end of the main air chest 50 being fastened to it in any desirable manner and the free ends of the branches or sections 51'are secured to an upright supporting member 78, which is fastened to the underside of the table in any desirable manner.

The carriage return As is well understood the typewriter carriage is usually returned to initial position when it reaches the end of each line written,

and the plat'enor cylinder thereof must be advanced so as to space the lines apart. This 'return movement of the carriage and adyancement ofthe platen is accomplished with the carriage return bellows device I, and the operation of said carriage return bellows de- 1 outer atmosphere. At places opposite the vice is controlled by the record sheet which brackets 79, which are fastened to the underside of the table in any desirable manner. The lower wall of the bellows is-stationary, being attached to the supports 7 9 and to the upper wall of the bellows is secured an arm 81, to which is fastened one end of a flex: ible connection 82 such as a cord,.wire, or the like and said flexible connection is trained over a pullev 83 rotatively mounted in the upper end of a post or standard 84 and the other end of said flexible connection is secured to the line space and carriage return lever 85 ofthe typewriter carriage. As is well understood the line space and carriage return lever of the tvpewriter is operatively connected'to the platen or cylinder in such manner that when the lever is forced in the direction to return the carriage. it automatically rotates the platen to provide the space between the lines. With the bellows device illustrated, the return of the carriage is accomplished whenever the air in the bellows is exhausted and the bellows collapsed as a re-' sult thereof.

The interior of the bellows is connected to the vacuum pump H bv a conduit 86 preferablv in the form of a flexible tube. which tube leads from a valve case 87 of the bellows device to the main suction tube 55. The valve case 87 is formed with suitable passages and provided with one or more valves for controlling the passage of outside air to and from the interior of the bellows and for establishing communication between the interior ofthe bellows and the vacuum pump and the valve mechanism illustrated will now be described.

The conduit or suction tube 86 connects with a va uum chamber 88in the case through a nipple 89. and the vacuum chamber 88 leads through one or more ports 91 to an air pasair chest, and the head of each poppet valve is i normally held upon a seat around the port 91 due to the partial vacuum created in the vacuum chamber 88 by the vacuum pump. The

air passage 90 communicates with a port 93,

which opens to the interior of the bellows and also communicates through ports 95, with an air inlet passage 94, which leads to the ends of the stems of the poppet valves 92 are flexible diaphragms 97 which are-secured to to the wall of the vacuum chamber 88 and below said flexible diaphragms are recesses or pockets 98, which communicate with a passage 99 through suitable ports, and from the passage 99 leads an air conduit or air tube 100, which leads to the slot 03 in the tracker bar that controls the operation of the carriage return bellows. A restricted orifice 99 is provided between the vacuum chamber 88 and passage 99. The air tube 100 is provided with a pneumatically controlled valve 190 (see Fig. 7) as will be hereafter explained, which is normally open, but which is closed whenever the record is being rewound so as to prevent the bellows I from being actuated as the perforations in the recordpass the slot d, in the tracker bar, which controls the operation of the carriage return bellows. The operation of the pneumatically controlled valve mechanism in the bellows device I, is practically the same as that of the valve mechanism in the air chest. It will, of course, be understood that the exact construction and arrangement of the valves forc'ontrollingthe action of the bellows is not material to this invention broadly considered, but it has been chosen for the purpose' of illustrating the invention. i

As has been explained, whenever the carriage return bellows operates to return the carriage to initial position, the air motor is stopped and therewith movement of the record stops. In order to start the motor again after the carriage has been returned, it is necessary to open the passageway through conduit or suction pipe 101 from the vacuum pump to the motor, and the means illustrated for controlling the action ofthe motor. will now be described. The motor control Referring now to Figs13, 15, 16, 17, 21 and 29. The air motorD is connected to the vacuum pump H by conduit, here shown in the form of a flexible suction tube 101, which leads from the air 'motor to a governor K and thence to the main suction tube 55. During the operation of the air motor the passage way through the conduit or tube 101 is open from end to,end, and valve mechanism is,

provided in said governor K for opening and closing the passage through said conduit or suction tube 101, and said valve mechanism is controlled from the tracker bar and. also from manually operated valves as will appear later. The suction tube 101 from the air motor enters the case 102 of the governor through a nipple 103 and leads away from the case of the governor "through a nipple 104. In the case 102 of the governor K is an L shaped pas sage 105 into one branch of which enters the nipple 103 of the'air motor suction pipe 101. The other branch of said L shaped passage nipple 107 which projects into the vacuum I chamber 106. At a place opposite the port or passage formed by the nipple 107 is a recess or pocket 108 and between said recess'and nipple 107 is a flexible diaphragm 109, which is secured to one wall of the case 102. Leading from said recess or pocket 108 is an air conduit, which preferably comprises a flexible tube 110 which leads to a pneumatically controlled valve 10 in the governor and thence through tubes 110, 110, to the slot c in the tracker bar. A branch tube 110 leads to a manually operated valve 111 (see Fig. 29). Between said recess or pocket 108 and vacuum chamber 106 is a restricted orifice 108 through which vacuum in the chamber 106 may extend to the recess 108 and air tube 110 and its branches whereby when vacuum is maintained in the chamber 106, recess 108, and air tube 110 and its branches, the flexible diaphragm 109 may remain inert with the port to the L shaped passage 105 uncovered. It will be understood that in case air is admitted to the branch 110 of the air tube 110 the flexible diaphragm will be forced across the port of the nipple 107 to the air passage 105, thereupon closing communication from the vacuum pump to the air motor.

A. passage 112 leads from the vacuum chamber 106 to the interior of the bellows 113 (see Fig. 21) and from the interior of the bellows a T shaped passage 114 (see Fig. 20) extends through the case wall 102 and communicates with the nipple 104 which connects with the suction tube 101 that runs to the vacuum pump. The valve controlled conduitbetween the air motor and vacuum pump may be readily traced in Figs. 17, 20 and 21, the arrows in said figures indicating the direction of a movement of air from the air motor to the vacuum pump.

The bellows 113 is provided with meansfor applying tension thereto and as shown in Fig. 17 a flat spring 115 is used for this purpose, one end being in engagement with a socket member 116 on the movable wall of the bellows 113 and its other end in engagement flexible diaphragm 109 remains inert, the" passage 105 to the air motor is open, thereby permitting the motor to operate under the influence of the vacuum pump, but when the flexible diaphragm is forced across the port in the nipple 107, the passage through the conduit to the air motor is closed andthe motor thereupon stopped.

As has been explained the operation of the air motor is controlled by the presence or absence of air under atmospheric pressure in the recess or pocket 108 behind the flexible diaphragm 109, and the admission of air to said recess is automatically controlled by the carriage upon its return to initial position at the beginning of a line, and it is also controlled by the valve 130 which is manually operated. This manually operated valve is used whenever it is desired to start the motor when it has been stopped under the control of the record sheet and has not been started automatically. In this conis at rest and consequently the record is stationary. At this time a perforation in the record is in register with the slot 0 in the tracker bar, which communicates with the valve control mechanism of the carriage return bellows device and air is being admitted to'the recess 108 behind the diaphragm 109. Consequently the diaphragm at this time is covering the port to the passage 105 and communication between the vacuum pump and motor is closed. As soon as the carriage is returned to its initial position, the air motor is again automaticaly started and the means for automatically starting the air motor at this time is controlled by the carriage of the typewriter and said mechanism will now be described.

Carriage controlled valve for starting air motor Mounted adjacent the'typewriter is an-air valve 122, which is normally closed to the outer atmosphere but arranged to be opened by the typewriter carriage uponits return to its initial position at the commencement of a line. The air conduit 127 from said valve leads through the governor K. For convenience said valve 122 is mounted upon the typewriter frame A (see Figs. 1 and 26) and as illustrated is-arranged to be opened by a rod 123, which forms art 'of the typewriter. The rod, here shown or actuating the valve 122, is the margin stop rod of the typewriter, which rod is usually fixedly secured in the standard typewriter on which it is shown, but-which is movable in an endwise direction for actuating the valve 122. As is well understood the margin stop rod .contains a stop shoulder 124,.which is adjustable lengthwise on the margin stop rod so as to determine the margin or place at which the carriagev stops when returned to initial position. A shoulder 125 on the carriage co-acts with said shoulder 124 to stop the carriage. In the present instance the rod 123 has a limited amount of endwise movement and spring back and cover the inlet opening to the valve whenever the rod 123 is retracted.

The air conduit 127 leading from the air valve 122 and from many of the other control valves are contained in the governor K, which will now be described.

The governor Referring now to Figs. 15 and 21 inclusive, the governor K will .be seen to comprise the bellows 113, the valve control means for the suction tube of the air motor hereinbefore described and certain other valve controls for the air conduits. In the upper portion of the governor are four similar pneumatically controlled valve devices is, 10 ,70 ,70 each havin its own function to perform, but all being substantially similar in construction. Each valve device ust mentioned comprises a flexible diaphragm 131 (see Fig. 18) located between a vacuum chamber 132 in the governor case K and a recess or cavity 133 behind each individual flexible diaphragm 131. A conduit or air passage 134 leads from the recess 133 and from said air passage 134 of valve device lc,jleads an air tube or other flexible air conduit 196, which runs to the slot 6 in the tracker bar. A restricted orifice 136 is provided between the air passage 134 and vacuum chamber 132 whereby when the passage through the air tube to the air passage 134 is closed, the vacuum in the vacuum chamber 132 may extend to the recess behind the flexible diaphragm 131 and the air tube connected therewith, so that the vacuum on both sides of the diaphragm 131 is balanced whereby said-flexible diaphragm may lie in an inert condition. Leading v through one wall of the vacuum chamber 132 at a place in front of each flexible diaphragm 131, is a pair of nipples 137 138, each pair forming part of-an air conduit having flexible air tubes or conduits connected therewith which lead to associated valve devices. Said nipples 137, 138 do not open into the vacuum chamber 132,

but the open end of each pair form a gap in the air line, and are arranged to be covered by a flexible diaphragm valve 139, which separates said vacuum chamber 132 from each pair of nipples 137, 138 and forms a closed cavity 139 into which said nipples do open, thereby forming a continuous passage through the air conduit entering the cavity through said nipples which passage may, however, be closed by forcing the flexible diaphragm valve 139 over the open end of either 7 duit will be closed whenever said flexible diaphragm valve is forced across the end of one or both nipples of the pair. The action of 7; these parts is such that when a partial vacuum is created in the vacuum chamber 132, said vacuum extends to any of the recesses or cavities 133 behind the flexible diaphragms 131,

so long as the passage through the tube, connected with the recess behind its associated flexible diaphragm 131 is closed,and theflexible diaphragms will therefo-reremain in inert 7 conditions. When, however, air is admitted into any recess behind a diaphragm, that diaphragm will be forced against the flexible diaphragm valve 139 thereby closing the passage through the air conduit controlled by the particular pneumatic valve de vice, which has been set into action by the admission of air to the recess behind the flexible diaphragm 131. The air conduits which lead from the several pneumaticcontrolled valve devicesJc, 70 70 will be described later in connection with the device to which they are connected.

The air conduit 158, which leads through the pneumatic valve device 70 is normally open to the outer atmosphere, asiseen in Figs.

15 and 17. Said conduit 158 leads to a recess 159 in the governor K, and located behind a flexible diaphragm 160, which is secured to one wall of'the vacuum chamber 132. The vacuum chamber 132 extends from the top of the governor case to a partition 161, which partition separates the vacuum chamber 132 from the vacuum chamber 106 (see Fig. 17) The vacuum chamber132 communicates with the interior of the bellows 113 through a port 162, but the flexible diaphragm valve 160 nor mally closes said port, and opens the passage.

through said port during the interval that the air motor is rewinding the record, whereby air may pass through both ports 114 and 162 at such times. At that time air is being admitted to the vacuum recess of the pneumatic valve device 70 whereby the diaphragm thereof is forced against the diaphragm valve thereof, closing the passage through the air conduit 158,3vherehy'the vacuum in the chamber 132 may extend to the recess 159 behind the diaphragm 160, thus permitting said diaphragm to become inert and allowing air to be exhausted through the port 162 as Well as theport 114. This is sometimes necessary because the movable wall of the bellows 113 may be set so close to the stationary wall as to bring the valve disc 119 very close to the nipple 120 of the port 114; whereby the opening to said port is somewhat restricted in size. By providing the additional passage through the port 162 air may freely move from the air motor through the ports and passage 105, 106, 112, 11 1, 162, to the interior of the bellows 113 and on to the vacuum pump H, which occurs when the air motor is rewindin the record. 7

As has eerl explained the pneumatic valve devices k, 70?, 70 70 are similar in construction and operation. The flexible diaphragm 131 of each pneumatic valve device normally lies inert, because the vacuum in the vacuum chamber 132 extends through each restricted orifice 136 to each vacuum recess 133 behind each flexible diaphragm 13land the vacuum on both sides of the flexible diaphragm is balanced. The vacuumin each vacuum recess 133 is maintained so long as the air conduit to it remains closed and said conduits remain closed, except when some port thereto at any place in its length is opened. Such port may be opened by a perforation in the record sheet, when it uncovers a certain slot in the tracker bar, or it may be opened whenizthe button of one of the manually operated valves is depressed, or it may be opened when one of the air valves is opened by some automatically operating mechanism. As long as the flexible diaphragm remains inert the passage throughsthe air conduit which is controlled by the pneumatic valve device, remains open since the diaphragm valve 139 at such time does not close the inlets to the nipples which connect with such air conduit, but 4 when airis admitted into the vacuum recess, the balanced vacuum condition on both sides of the flexible diaphragm is overcome by the incoming air and said diaphragm is forced against said diaphragm valve, closing the inlets to said nipples thereby closing the passage through saidair conduit. Closing the passage through said air conduit causes the flexible diaphragm of the actuated'pneumatic valve device connected to said air conduit to become inert because the vacuum on both sides of such flexible diaphragm becomes balanced whereby the air conduit controlled by such actuated pneumatic valve device is opened to permit the passage of air therethrough, 7

The air conduit 196.,from the pneumatic valve device 70 leads to the slot 6, of theitracker bar and controls the air passage through the air conduit 127, 129 and its branch 129.

"Whenever the slot 6, is uncovered, the vacuum in the pneumatic valve device 70 becomes unbalanced, and the diaphragm valve thereof closes the passage-through said air conduits 127, 129, 129 which prevents the motor from being started when the valve 122 is opened byithe carriage at the commencement of a new line.- .This allows the attendant to write any desired matter into the body of the letter at this place. The air conduit 197 bellows allowed to expand and to shift the pinion back into mesh with gear wheel 39 and thereby end the rewind operation and start the winding operation. Simultaneously a balanced vacuum condition is restored in the pneumatic valve device of the action G, and the carriage return bellows device I are both of them restored to working condition. The air conduit 129 from the pneumatic valve device k leads to conduit 129 and controls the passage through the air conduits 110*, 110*. Whenever air is admitted to the pneumatic valve device k through air conduit 129 the air passage through conduit 110- is closed, and as a consequence the balanced vacuum condition for the valve 109 is restored, and the port through the suction conduit thereby opened, whereby the motor is started. Air may be admitted to said conduit 129 by opening valve 130. It is also admitted to-conduit 129 when the valve 122 is opened. The air conduit 154 from the neumatic valve device leads through conduit 154 to the slot j, in the tracker bar and also leads to the conduit 154 at the pneumatic valve device 10 and controls the open air passage through the conduit 158. Whenever air is admitted to the pneumatic valve device 10 the auxiliary port-162 in the suction con-.

duit to the air motor is opened. Air is admitted to the valve device 70 through conduit 154 whenever the slot 7' is uncovered; also when valve 193 (operated by the clutch shifting bellows device J) is opened.

The clutch shifting bellows After a letter or other instrument has been completely written, the record or record sheet is rewound on the roll 41 by the rewind mechanism hereinabove described and a perforation or a series of perforations are made in said record or record sheet at the end of the perforations, (which control the operation of the typewriter) and said perforation is arranged to come into register with a slot Z, in the tracker bar, whereupon valve mechanism, contained in the clutch shifting bellows device J, is opened to establish communication between the interior of the bellows and the vacuum pump, whereby the air may be exhausted' from said bellows and the clutch shifting lever may be thereby actuated. Re ferring now to Figs. 1, 2, 24, 25 and 29, the clutch shifting bellows device J will be seen to comprise a bellows 140, which for convenience is illustrated as secured to one of the upright frame members 26, andsaid bellows device is provided with a pneumatically controlled and operated valve device substantially similar to the valve control device of the carriage return bellows device. The suction tube 141 for the clutch shifting bellows device J, which as shown, leads from the main suction tube 55, enters the valve case 142 of the clutch shifting device J through a port, which opens into a vacuum chamber 143, from which leads a port 144 that is normally covered by a poppet valve 145. The port 144 opens into an intermediate vacuum chamher 146, which communicates with the interior of the bellows 140 through a port 147. In the wall 148 of the bellows 140 is an air inlet passage 149 which opens to the external atmosphere and terminates in a port behind the head of the poppet valve 145. Normally air, at atmospheric pressure, may enter the bellows through the passage 149,-the intermediate vacuum chamber 146, and port 147. As in the other pneumatically controlled valve devices, there is a recess 150 behind. the stem of the poppet valve 145, and a flexible diaphragm 152 is secured to the inner face of the valve case and separates said recess 150 from the vacuum chamber 143. An air passage 153 leads from said recess and connects with the flexible tube or air conduit 154, and a restricted orifice 155 is provided between said passage 153 and vacuum chamber 143, whereby when vacuum is created in the vacuum chamber 143 it may extend to the recess 150 and conduit or air tube 154 whenever the passage through said tube is closed. The result is, that when in operation, the vacuum pump exhausts the air from the vacuum chamber 143 thereby closing the port between the intermediate vacuum chamber 146 and the vacuum chamber 143 and at the same time uncovering the port to the air passage 149. This permits air at atmospheric pressure to enter the bellows 140 and expand them. Whenever the passage through the air tube 154 is opened, air at atmospheric pressure is admitted into the recess 150 and as a result the flexible diaphragm forces the poppet valve off its seat thereby closing the air inlet passage 149 and establishing communication between the interior of the bellows and vacuum chamber 143, through the port 147, intermediate vacuum chamber 146 and port 144 and permitting the air to be exhausted from the bellows, which collapse under the force of the external pressure, thereby operating the clutch shifting lever through a suitable connection, which as shown, comprises an arm 156 mounted on the movable wall of the bellows and connected-with the clutch lever 48 by a link 157. The coil tension spring 49 connected with the arm 156 acts to return the arm and bellows to normal position whenever the vacuum in the bellows is released.

The air conduit 154 from the valve mecha- 7 nism of the clutch shifting bellows device J runs to the diaphragm valve of the pneumatic valve device 10 of the governor K. From the pneumatic diaphragm valve device k the branch air conduit 154 leads to the vacuum recess behind the diaphragm of the pneumatic valve device la which controls the operation of the diaphragm valve 160 for the auxiliary port of the air motor suction conduit. The branch 154 is connected to the main air conduit 154 for the clutch shifting bellows device J and said air conduit 154 leads to the slot 7', of the tracker bar. The branch 154 leads from the branch 154 and runs to an air valve 192 operated by the clutch shifting bellows. The other branch 154 connects with the air conduit 154 and leads to a pneumatic valve device 190, (see Fig. 7) which controls the assage of air through the air conduit 100 or the carriage return bellows device I. Another branch 154 connects with the main air line 154 or one of its branches, as for instance branch 154 and leads to the manually operated valve 180. So long as the slot 9', of the tracker bar is covered, the valve devices associated with the air conduit 154 and its branches are closed, but when a perforation of the record sheet uncovers said slot 7', air is admitted. to the air conduit 154 and thence to its branch 154 and branch 154 and to the vacuum recess 150 of the pneumatic valve device in the clutch shifting bellows device J, whereby the port to the suction tube 141 thereof is opened and the air is exhausted from the said bellows, and the clutch lever 48 for the rewind mechanism is shifted, whereupon the rewind gearing is set in motion and the record sheet is rewound. At the same time air is admitted to the branch 154 whereby air is admitted to the vacuum recess behind the diaphragm valve of the pneumatic valve device is, closing the normally open air pamage 158 to the recess behind the flexible diaphragm 160, and thereby permitting said diaphragm to become inert and uncover the port 162 to the bellows 113, thereby permitting a greater volume of air to pass from the air motor to the vacuum pump. At the same time air is admitted to the branch 154 of the air conduit 154 and to the vacuum recess behind the flexible dia hragm of the pneumatic valve device 190 (gee Fig. 7) wherebylthe air passage through the air conduit 100 to the carriage return bellows is closed, thereby preventing its operation during the interval that the record is rewound.

Leading from the slot 2', of the tracker bar is an air conduit 191, which runs to the vacuum recess behind the diaphragm valve 57 (see Fig. 7 which controls the passage through the port to the air'chest of the action and from said air conduit 191 leads a branch 191* that runs to an air valve 192 operated by the clutch shifting bellows device J (see Fig. 25) and from said branch 191 leads a branch 191', which runs to the manually operated air valve 179. It will be understood that by admitting air to the air conduit 191 or any of its branches the diaphragm valve 57 will'be permitted to close the main port 65 to the air chest thereby preventing is opera-' tion, and this takes place during the interval that the record sheet is being rewound.

As has been explained it is desirable that the various mechanisms which operate the typewriter remain quiescent during the interval that the record sheet is being rewound, and the air valve 192 and its air connections, which operate to render said mechanisms inactive at that time have been explained. Two other air valves 193, 194 are operated by the clutch shifting bellows device J and all three of said air valves are shown as contained in the stationary wall 148 of said bellows (see Figs. 24, 25). Said air valves may comprise air passages contained in said bellows wall 148 and closed 'by flexible-valve covers. The

movable wall of the bellows is provided with an arm or other actuating member 195, which is arranged to engage the covers of said valve 192, 198, 194, and simultaneously open said air valves whenever the bellows 140 are collapsed to shift the clutch and eflect the re wind operation. The air valve 192 controls the main port to the air chest and when opened closes said port and renders the key lever bellows inactive. The air valve 193 controls the pneumatic valve device of the clutch shifting bellows device J, and is opened when the bellows thereof are collapsed as a result of a perforation uncovering the slot 1', in the tracker bar. The perforation uncovers the slot momentarily and the bellows are therefore collapsed and the instant they are collapsed the arm 195 thereof opens the valve 193, thereby opening the air conduit back to the valve device of the bellows through the air' conduit 154, 154", 154. The air valve 194 controls the pneumatic valve device 72 for the air conduit 110 to the air motor suction conduit diaphragm valve 109, and while the air' valve 194 is held open, air is admitted to the pneumatic valve device 7%, the diaphragm valve closes the passage through the air tube 110*, renders the diaphragm valve 109 inert, thereby permitting the port 105 to remain open between the. two sections of the suction tube 101 from the vacuum pump to the air motor. This allows the motor to run and rewind the record without permitting the action G or carriage bellows device I to function during the rewindi operation.

The record aligning mechanism As is well understood it is important that the perforations of the record or record sheet be ke t in alignment with the inlet ports to the sl dtsof the tracker bar, and sometimes, due to warping of the record or from other 

